In the past, various forms of rock pickers have been proposed. In one very old form of such a device the picker consists of a vehicle having a driven reel, a fork table positioned forwardly of the reel and a bucket positioned forwardly of the fork table. In operation, the reel is rotated at great speed to impell rocks forwardly over the fork table and into the bucket. A rock picker of this nature is disclosed in Canadian Pat. No. 21,884 issued June 15, 1885 to B. A. Weatherbee. This type of mechanism has fallen into discuse since it was only capable of picking up small rocks and because the impeller reel arrangement was prone to miss many of the rocks that were being picked up.
In recent years the majority of rock pickers that have been proposed consist of a vehicle with a fork table mounted so as to skim rocks from a ground surface as the picker proceeds over the surface. These pickers conventionally include a lifting mechanism for the fork table arranged to move the table from its skimming position to a dumping position so as to dump collected rocks from the table into a bucket also carried by the vehicle. Additionally, bucket dumping mechanisms have been provided in these devices to empty the bucket when it became full. One rock picker of this type is disclosed in Canadian Pat. No. 692,573 issued Aug. 18, l964 to John C. Schindelka. The major disadvantage of this type of rock picker is that it can only skim rocks of certain sizes that are fully above the ground surface. If, for example, one wished to remove small rocks from a ground surface in which they are imbeded it would not be possible to simply skim them from the surface.